Pulsed stimulated Brillouin microscopy.

Stimulated Brillouin scattering is an emerging technique for probing the mechanical properties of biological samples. However, the nonlinear process requires high optical intensities to generate sufficient signal-to-noise ratio (SNR). Here, we show that the SNR of stimulated Brillouin scattering can exceed that of spontaneous Brillouin scattering with the same average power levels suitable for biological samples.

Forward Brillouin scattering acoustic impedance sensor using thin polyimide-coated fiber.

The standard single-mode fiber has been demonstrated as an optomechanical sensor recently to measure the acoustic impedances of surrounding liquids by means of the generation and detection of forward-stimulated Brillouin scattering (FSBS). FSBS allows the mechanical properties of an external material to be probed directly through the interaction of guided light and transverse sound waves that occurs entirely inside the fiber structure. In this technique, having a low-loss interface between the fiber bulk and the external medium is essential for precise measurement; however, it leads to the necessary but impractical removal of the thick polymer fiber coating in most reported methods.

Distributed forward Brillouin sensor based on local light phase recovery.

The distributed fibre sensing technology based on backward stimulated Brillouin scattering (BSBS) is experiencing a rapid development. However, all reported implementations of distributed Brillouin fibre sensors until today are restricted to detecting physical parameters inside the fibre core. On the contrary, forward stimulated Brillouin scattering (FSBS), due to its resonating transverse acoustic waves, is being studied recently to facilitate innovative detections in the fibre surroundings, opening sensing domains that are impossible with BSBS.

Local activation of surface and hybrid acoustic waves in optical microwires.

Elastic vibrations in subwavelength structures have gained importance recently in fundamental light-matter studies and various optoacoustic applications. Existing techniques have revealed the presence of distinct acoustic resonances inside silica microwires yet remain unable to individually localize them. Here, we locally activate distinct classes of acoustic resonances inside a tapered fiber using a phase-correlation distributed Brillouin method.

Photonic crystal fiber-based surface plasmon resonance sensor with selective analyte channels and graphene-silver deposited core.

We propose a surface plasmon resonance (SPR) sensor based on photonic crystal fiber (PCF) with selectively filled analyte channels. Silver is used as the plasmonic material to accurately detect the analytes and is coated with a thin graphene layer to prevent oxidation. The liquid-filled cores are placed near to the metallic channel for easy excitation of free electrons to produce surface plasmon waves (SPWs).